Setback switch



Jan. 4, 1949. T, M, PERRY 2,458,479

sETBAcx swITcH Filed April 28', `194:5

' l Lu l [6 N q c b /4 i [3 Il FG.3. `Fl 4 l x u /9 1! /6 i IlNvx-:N'roR f THOMAS M. PERRY LIEU! Patented Jan. 4, 1949 I I E u NLTEn; retener or Slieuffiex suggeriti t Themes; germ enpineeue, @esisteretaas, renreeeutesl.

Atiplieetiommirzs, meetinstrumenten (eleganza-52u S f l Thisinventionrelateato; switches-and more. erlthereim Theenumerat I0indicates, the body,

particularlytoisetbeelesvvitehes vthiehzerzetedeger- Qf the dey-ieeeWhhiA ferme@ Off Suitable inSur ed tobemountedin;expiosivenroimtiles;fonqlpsr letine; meterieduandxmeyvhe a.udrtionef a body ine. atieasua; portion an eleotrieeltdetpnetinef ef;ernennen on other component- Withinthe circuit. preiectileit Aboref II.extends,.- throughmhe'body The; prior artdevicesofitnisnature'havefbeen:maudiliesiarestrfeted eerbied '2f etzitsrear or dependent; uponVoperation;v btt movement; Qii nur mwetend,f.,K Ateilndricelfoontacttsleeve I.3, which merous, mechanical par-tsj.' Many; o fy; these; :newis formed of 'tubular copper or other suitablecpny ohanioai parts must4be. precision medeenei ine duetivefmeteliis ereeeifltted erdthertwisesecurely terttedin azcomparativelu s -melksreees- 'lheree 110# mountedWithin the herev Ll` Wire: L4., which fore.- it; hasrequired; mucha-imaandsvkiilitoimenefermsteue; Side...l Qf the; eleetrfieelg Circuit C, is,seluraotnie. setback. switches and; the eis-pensei-eederedienotherwieeseeuredfto-.thefeylindrical edn,- voived: has been.reiatizvseiyfhigh elsa. the seit-1 teet member I3 et 15- Wire.IIiivrhiehf-.ermsthe back switches of the prior art have usuallyfheen; rother;sidaoffthgaletricalgqigcuikcj'is mounted dependent uponatsingleepui-nttorconteet, which le* thrnuehthe-lestrietesiaeeeuinef I2et here. IeI and pointv off contact, fon some reason; on othemheeeistseeilielyfltelli 0F: @erweitert therein; by a; sleeve occasionallyfauceta to close,- tnef eleetrioalt cireuitr, I :lather sleeve Il beine:mess iteriiwithnf the; re,-

An object off thisinventiom isinreyide aisee Striatediegeeine; I.2.-.back switch.` whiohmayberzmquntedih; eeplgiy@ l Similmi. exble;metallic` csrtect wire projectiles to maintain; am electrischdetonaliinea 29 I 8 is secured to wire I6 by soldering; le;Theconeircuitopened untilftheipnojectilerhasebeen.firedi. '18,: entende.aiiiellyi. 'Ihecontaet: wire after which. the; acceleration:- ofthe,p1;ylijetzle;` L83 wllillprtmllhtfliemrrintherppsition, astshowncreating. e. setbackv force; wiiiect-.uatatbeiswitchi ini Figure@ 1.duef te] its: own: semi-resilience. but toclosethe circuit. it issuiiciently ductil-e so thatit mayybe easilyv Another object ofv the-Iinvention. isrtpmvidef 2% compressed or deformed into ilexble engageasetbackswitch wherein; a; pluralitysofcontis mme Witht the@Siugr,ophaling`v sleeyef; l;l-, and will will be made, any. oneoff whichwille-cloSe-fattleast; remettra in; ite detonmeg, position, A, plunger12 65 a portion of4 an electricalidetonatnemmcuit; preiegaplg, formed;or' insulating; material; is po- Anotherobject. ofthe invention is:` to:provider sitiorielwithim thefccntactsleeve, I3; and has a a setbackswitchwhichzis;extremely:simpleiin one qrelativelyf loose itg therein,However, the friceratlon, positive inX function, andi wherein; pre.tique-l' erigemnk between the plunger ZIJ and cision mademechanicalfparts.; are elminatedt theeeylndinal Contiwt, sleeve.AI3;is.sufi`1cient to Otherobjects of: the invention will' appearaftervproj/,ente longitudinak movement off the plunger an. inspection of thefollowing description. wlthiiui thrsieevfe; unders al1 normalzhandlingcon- In the drawings: mi dimmer. 0E'. thea pI-'Qjectim Whenthe projectiley is Figure 1 is a verticalz sectional:l viewfof' theme ned.fille: acceleratom thereor creates, suicient vention, showing thesamelmountedf.withinapo r..I setback.: ienne.V to; cause, the plungerZ0: to slide;

tion of an electrical detonating-circuit, the switch?l rearward within,the sleeve,.- lz33, toward4 the! 11e being-vin opened position;- 7stricted portion; l-Zlorbore hl.

Figure 2 is averti-cal-sectional-view of the -inplungen 2li; is.,provided; with. an axially vention showing the position of thev partswhen ppsitignedf, b or@` 2,1, fprnling; a pocket. which` ex'-` theswitch has been closed bythe-force; off' set;- tenlg; frein the.- rearfofi; the. plunger forwardly,

back created when the projectile-isredf:ll buittermnatesshort of: the:forward` end thereof. Figure 3, is a, perspective-view: rif:J ehielectrical 45 reen on lower end' off here..v 21a has an. out-A contactsleeve; f wardiy poration Itowillzbe apparent' by Figure 4 is. aperspeetiveviewotthe collapsible onefskliedsinitne ant; that-the formofrthe eared contact element; and, portions 22' may; be,l varied'V fromthat disclosed;

Figure 5 is an inverted= perspective view of'the and; obyiously; theform will; depend@ primarily plunger. my upom theilengthwfthe-bore 21kwithin the plunger Referring now to the. drawings, and particug- *2ltgthellengthof: the Contact.. wire L8: and'. the lar-lyvv to Figure 1thereof, it willheseen thajgthe diameteuoifcqntactsleeva I3. switchwhich forms the subject matter of' this n- The operation? olif the.deyice will be, readily vention is adapted to be mounted in anelectrical under stocd'-from the. foregoing description. The detonatingcircuit C, the circuit having a prox- 55 plunger 20 is positioned withinthe contact sleeve imity fuze and a source v,of current B incorporat- I3so that the contact wire I8 will extend within 3 the bore 2I of plunger20. When the parts are in this position, as shown in Figure 1, thecircuit is broken because of the space between contact wire I8, whichforms an extension of one side of the circuit, and contact sleeve I3,which forms an extension of the other side of the circuit. When theprojectile is fired, the setback f orce created by the accelerationofthe projectile'.forces the' plunger rearwardly. As the plunger movesrearwardly, the contact wire I8 will bend and` tact sleeve in spacedrelation thereto and having assume the position as shown in Figure 2.When a portion thereof extending into said bore in said in thisposition, the wire I8 will make a plurality .Y

of contacts with sleeve I3, thus closing the cirthe projectile strikingan object aftrfbeing rje cuit C. In caseof reverse setback, 'occasionedbynf,"

the plunger 2D will move forwardly, but in view' of the fact that thewire I8 isnot directly con- ""F nected to the plunger 28, the forwardmovement of the plunger will not affect the wire I8, and thev latterwill remain in its collapsedposition, thus maintaining circuit C closed.lIt`wi1l be under'- stood that while three points of contactI are shownbetween wire I8 and sleeve I 3, a largery or smaller number of contactsmay be obtained by varying the length of wire I8 or its resilience,varying the diameter oi sleeve I3, or varying the length of bore 2|and/or the shape of the iared portion 22 thereof. n

From the foregoing description, it will be seen that the subject matterof this invention is ex'- tremely simple in operation andr positive infunction, and that it can be easily and cheaply made and assembled. 7

One of the particular advantages of my improved setback switch is thatit will not be operated by repeated small shocks. That is to say, if theswitch is jarred it will be reset to its normal inoperative condition bythe action of the spring wire I8, which will move the plunger 20 to itsoriginal position. f f It is also desired to point out that my improvedswitch may be easily short-circuited for the purpose of testing acomplete circuit in which the switch may be wired. I claim:

1. A setback switch adapted to be mounted within a projectile to closeat least a portion of an electrical detonating circuit upon theapplication of setback force created when the projectile is redcomprising a body member, a bore in said body member, an electricalcontact sleeve posi-` tioned within said bore, elongated bendablecontact means mounted in said body member and extending within saidcontact sleeve in spaced relation thereto, and a plunger positionedwithin said sleeve capable of sliding therein upon the application ofsetback force for bending said elongated contact means into a pluralityof contact engagements with said contact sleeve. i s 2. A setback switchadapted to bev mounted within a projectile to close at least a portionof an electrical detonating circuit upon the application of setbackforce created when the projectile is ired comprising a body member, abore in saidbody member, an electrical contact sleeve positioned withinsaid bore, a wire mounted in saidV body member and extending within saidcontact sleeve in spaced relation thereto, and a plunger positionedwithin said sleeve capable of sliding therein upon the application ofsetback force .for bending said wire to make a plurality of contactsbetween said wire and said contact sleeve.

-3. A setback switch adapted to be'.rnounted 4 within a projectile toclose at least a portion of an electrical detonating circuit upon theapplication of setback force created when the projectile is redcomprising a body member, a bore in said body member, an electricalcontact sleeve positioned within said bore, a plunger positioned Withinsaid sleeve capable of sliding therein uponthe application of setbackforce, a bore in said plunger, and a wire mounted in said body memberand extending axially within said conplunger, the sliding movement ofsaid' plunger ywithingsaid sleeve causing said wire to bend andmakjaplurality of contacts with said contact sleeve.'

m14.v A setback switch adapted to be mounted within a projectile toclose at least a portion of an electrical detonating circuit upon theapplication of setback force created when the projectile is iiredcomprising a body member of insulating material, a bore in said bodymember, an electrical contact sleeve positioned within said bore, aplunger positioned within said sleeve capable of sliding therein uponthe application of setback force, a bore in said plunger having anoutwardly ared portion at its outer end, and a wire mounted in said bodymember and extending withincontact sleeve in spaced relation thereto andhaving a portion thereof extending into said bore in said plunger, thesliding movement of said plunger causing said wire to bend outwardly tomake a plurality of contacts with said contact sleeve.

5. A. setback switch adapted to be mounted within a projectile to closeat least a portion of anl electrical detonating circuit upon theapplication of setback force created when the projectile is firedcomprising a body member of insulating material, a bore extendingthrough said body member, said bore having a, restricted portion at itslower end, an electrical contact sleeve positioned within said bore,adapted to be connected to one side of the electrical detonatingcircuit. a plunger positioned within said sleeve capable of slidingtherein upon the application oi setback force. a bore having anoutwardly flared portion in said plunger, and a wire mounted in saidbody member extending axially within said contact sleeve in spacedrelation thereto, and having a portion thereof extending into said borein said plunger, said wire entering the body member through therestricted portion of said bore, and forming an extension of the otherside of the electrical detonating circuit, the sliding movement of saidplunger causing said wire to bend outwardly to make a plurality ofconta-cts with said contact sleeve.

THOMAS M. PERRY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS `6&5

Number Name Date 1,845,848 Richards Feb. 16, 1932 2,420,028 I BleakneyMay 6, 1947 FOREIGN PATENTS .70 Number Country Date YFrance Aug. 25,1925

